The study published December 21, 2015 in the journal NANO Letters describes the device. The micromotor is made of special polymer with a double layer of nickel and titanium, which allows it to be activated by a rotating magnetic field. The American Chemical Society published a video showing an in vitro spermatozoid being driven using this technique.

In vitro, the first step is to capture the spermatozoid, thus the tail of the sperm must be inserted inside the coil with the head positioned in front. Then, the coil surrounding the sperm’s tail transports it and drives it to the egg. Once the destination is reached, near the ovocyte wall, the coil is propelled in the opposite direction to liberate the sperm to fertilize the egg. Without this micromotor, the spermatozoid would be unable to move.

If researchers can totally master this new technique, which effectiveness and safety remain to be proven, fertilization can be carried out directly in the uterus, but as the journal, Futura Sciences cites, “this technique is still far from being usable clinically”.